A standard motor-vehicle door latch comprises a bolt attached to and extending perpendicularly from the doorpost and a latch on the door edge. The latch has a pivotal fork that engages around the bolt to secure the door tightly in place.
The bolt is typically part of a bolt assembly comprised of a metallic U-shaped yoke having an inner flange bolted to the doorpost and an outer flange spaced therefrom, forming a fork-receiving space therewith, and having an outer surface turned away from the inner flange. The bolt is also metallic and is permanently fixed to the two flanges so as to extend generally perpendicular therebetween.
When the door is closed the outer surface of the outer flange normally contacts the door, and of course the metallic latch fork engages over the metallic bolt. This metal-to-metal contact is noisy, and also leads to abrasion and some damage to the metal, leaving sharp edges.
In my copending application OH 203,245 filed Jun. 6, 1988, now U.S. patent Ser. No. 4,834,435 issued May 30, 1989, I describe an improved system wherein a nonmetallic resilient sleeve surrounds the bolt between the flanges of the yoke and a nonmetallic cover overlies at least the outer surface of the outer flange. Thus with the system of this earlier invention the bolt is cushioned so that it will cooperate with the fork quietly, and the surfaces of the yoke that engage the door edge are similarly cushioned. Even when a second sleeve of a material substantially more resistant to wear than the first sleeve surrounds the first-mentioned sleeve the noise that this latch makes is substantially reduced.
Such a construction still is likely to squeak and rattle slightly. Even though the contact between the fork and the bolt is cushioned somewhat, there remains substantial room for the creation of play and metal-to-metal contact.